The use of cursor measures for motion-impaired computer users

“Point and click” interactions remain one of the key features of graphical user interfaces (GUIs). People with motion-impairments, however, can often have difficulty with accurate control of standard pointing devices. This paper discusses work that aims to reveal the nature of these difficulties through analyses that consider the cursor’s path of movement. A range of cursor measures was applied, and a number of them were found to be significant in capturing the differences between able-bodied users and motion-impaired users, as well as the differences between a haptic force feedback condition and a control condition. The cursor measures found in the literature, however, do not make up a comprehensive list, but provide a starting point for analysing cursor movements more completely. Six new cursor characteristics for motion-impaired users are introduced to capture aspects of cursor movement different from those already proposed.

Using cursor measures to determine appropriate computer input assistance for motion-impaired users

People with motion-impairments can often have difficulty with accurate control of standard pointing devices for computer input. The nature of the difficulties may vary, so to be most effective, methods of assisting cursor control must be suited to each user's needs. The work presented here involves a study of cursor trajectories as a means of assessing the requirements of motion-impaired computer users. A new cursor characteristic is proposed that attempts to capture difficulties with moving the cursor in a smooth trajectory. A study was conducted to see if haptic tunnels could improve performance in "point and click" tasks. Results indicate that the tunnels reduced times to target for those users identified by the new characteristic as having the most difficulty moving in a smooth trajectory. This suggests that cursor characteristics have potential applications in performing assessments of a user's cursor control capabilities which can then be used to determine appropriate methods of assistance.

Perception and haptics

For people with motion impairments, access to and independent control of a computer can be essential. Symptoms such as tremor and spasm, however, can make the typical keyboard and mouse arrangement for computer interaction difficult or even impossible to use. This paper describes three approaches to improving computer input effectivness for people with motion impairments. The three approaches are: (1) to increase the number of interaction channels, (2) to enhance commonly existing interaction channels, and (3) to make more effective use of all the available information in an existing input channel. Experiments in multimodal input, haptic feedback, user modelling, and cursor control are discussed in the context of the three approaches. A haptically enhanced keyboard emulator with perceptive capability is proposed, combining approaches in a way that improves computer access for motion impaired users.

Research review: reading comprehension in developmental disorders of language and communication

Background: Deficits in reading airment (SLI), Down syndrome (DS) and autism spectrum disorders (ASD). Methods: In this review (based on a search of the ISI Web of Knowledge database to 2011), the Simple View of Reading is used as a framework for considering reading comprehension in these groups. Conclusions: There is substantial evidence for reading comprehension impairments in SLI and growing evidence that weaknesses in this domain are common in DS and ASD. Further, in these groups reading comprehension is typically more impaired than word recognition. However, there is also evidence that some children and adolescents with DS, ASD and a history of SLI develop reading comprehension and word recognition skills at or above the age appropriate level. This review of the literature indicates that factors including word recognition, oral language, nonverbal ability and working memory may explain reading comprehension difficulties in SLI, DS and ASD. In addition, it highlights methodological issues, implications of poor reading comprehension and fruitful areas for future research.

Reading comprehension in autism spectrum disorders: The role of oral language and social functioning

Reading comprehension is an area of difficulty for many individuals with autism spectrum disorders (ASD). According to the Simple View of Reading, word recognition and oral language are both important determinants of reading comprehension ability. We provide a novel test of this model in 100 adolescents with ASD of varying intellectual ability. Further, we explore whether reading comprehension is additionally influenced by individual differences in social behaviour and social cognition in ASD. Adolescents with ASD aged 14-16 years completed assessments indexing word recognition, oral language, reading comprehension, social behaviour and social cognition. Regression analyses show that both word recognition and oral language explain unique variance in reading comprehension. Further, measures of social behaviour and social cognition predict reading comprehension after controlling for the variance explained by word recognition and oral language. This indicates that word recognition, oral language and social impairments may constrain reading comprehension in ASD.

Facilitating and disrupting speech perception in word deafness

Background: Word deafness is a rare condition where pathologically degraded speech perception results in impaired repetition and comprehension but otherwise intact linguistic skills. Although impaired linguistic systems in aphasias resulting from damage to the neural language system (here termed central impairments), have been consistently shown to be amenable to external influences such as linguistic or contextual information (e.g. cueing effects in naming), it is not known whether similar influences can be shown for aphasia arising from damage to a perceptual system (here termed peripheral impairments). Aims: This study aimed to investigate the extent to which pathologically degraded speech perception could be facilitated or disrupted by providing visual as well as auditory information. Methods and Procedures: In three word repetition tasks, the participant with word deafness (AB) repeated words under different conditions: words were repeated in the context of a pictorial or written target, a distractor (semantic, unrelated, rhyme or phonological neighbour) or a blank page (nothing). Accuracy and error types were analysed. Results: AB was impaired at repetition in the blank condition, confirming her degraded speech perception. Repetition was significantly facilitated when accompanied by a picture or written example of the word and significantly impaired by the presence of a written rhyme. Errors in the blank condition were primarily formal whereas errors in the rhyme condition were primarily miscues (saying the distractor word rather than the target). Conclusions: Cross-modal input can both facilitate and further disrupt repetition in word deafness. The cognitive mechanisms behind these findings are discussed. Both top-down influence from the lexical layer on perceptual processes as well as intra-lexical competition within the lexical layer may play a role.  

Speech-like and non-speech lip kinematics and coordination in aphasia

Background and aims: In addition to the well-known linguistic processing impairments in aphasia, oro-motor skills and articulatory implementation of speech segments are reported to be compromised to some degree in most types of aphasia. This study aimed to identify differences in the characteristics and coordination of lip movements in the production of a bilabial closure gesture between speech-like and nonspeech tasks in individuals with aphasia and healthy control subjects. Method and procedure: Upper and lower lip movement data were collected for a speech-like and a nonspeech task using an AG 100 EMMA system from five individuals with aphasia and five age and gender matched control subjects. Each task was produced at two rate conditions (normal and fast), and in a familiar and a less-familiar manner. Single articulator kinematic parameters (peak velocity, amplitude, duration, and cyclic spatio-temporal index) and multi-articulator coordination indices (average relative phase and variability of relative phase) were measured to characterize lip movements. Outcome and results: The results showed that when the two lips had similar task goals (bilabial closure) in speech-like versus nonspeech task, kinematic and coordination characteristics were not found to be different. However, when changes in rate were imposed on the bilabial gesture, only speech-like task showed functional adaptations, indicated by a greater decrease in amplitude and duration at fast rates. In terms of group differences, individuals with aphasia showed smaller amplitudes and longer movement durations for upper lip, higher spatio-temporal variability for both lips, and higher variability in lip coordination than the control speakers. Rate was an important factor in distinguishing the two groups, and individuals with aphasia were limited in implementing the rate changes. Conclusion and implications: The findings support the notion of subtle but robust differences in motor control characteristics between individuals with aphasia and the control participants, even in the context of producing bilabial closing gestures for a relatively simple speech-like task. The findings also highlight the functional differences between speech-like and nonspeech tasks, despite a common movement coordination goal for bilabial closure.

Fundamental deficits of auditory perception in Wernicke’s aphasia

Objective: This work investigates the nature of the comprehension impairment in Wernicke’s aphasia, by examining the relationship between deficits in auditory processing of fundamental, non-verbal acoustic stimuli and auditory comprehension. Wernicke’s aphasia, a condition resulting in severely disrupted auditory comprehension, primarily occurs following a cerebrovascular accident (CVA) to the left temporo-parietal cortex. Whilst damage to posterior superior temporal areas is associated with auditory linguistic comprehension impairments, functional imaging indicates that these areas may not be specific to speech processing but part of a network for generic auditory analysis. Methods: We examined analysis of basic acoustic stimuli in Wernicke’s aphasia participants (n = 10) using auditory stimuli reflective of theories of cortical auditory processing and of speech cues. Auditory spectral, temporal and spectro-temporal analysis was assessed using pure tone frequency discrimination, frequency modulation (FM) detection and the detection of dynamic modulation (DM) in “moving ripple” stimuli. All tasks used criterion-free, adaptive measures of threshold to ensure reliable results at the individual level. Results: Participants with Wernicke’s aphasia showed normal frequency discrimination but significant impairments in FM and DM detection, relative to age- and hearing-matched controls at the group level (n = 10). At the individual level, there was considerable variation in performance, and thresholds for both frequency and dynamic modulation detection correlated significantly with auditory comprehension abilities in the Wernicke’s aphasia participants. Conclusion: These results demonstrate the co-occurrence of a deficit in fundamental auditory processing of temporal and spectrotemporal nonverbal stimuli in Wernicke’s aphasia, which may have a causal contribution to the auditory language comprehension impairment Results are discussed in the context of traditional neuropsychology and current models of cortical auditory processing.

Speech therapy after stroke: trial shows only that practice varies

Bowen and colleagues’ methods and conclusions raise concerns.1 At best, the trial evaluates the variability in current practice. In no way is it a robust test of treatment. Two communication impairments (aphasia and dysarthria) were included. In the post-acute stage spontaneous recovery is highly unpredictable, and changes in the profile of impairment during this time are common.2 Both impairments manifest in different forms,3 which may be more or less responsive to treatment. A third kind of impairment, apraxia of speech, was not excluded but was not targeted in therapy. All three impairments can and do co-occur. Whether randomised controlled trial designs can effectively cope with such complex disorders has been discussed elsewhere.4 Treatment was defined within terms of current practice but was unconstrained. Therefore, the treatment group would have received a variety of therapeutic approaches and protocols, some of which may indeed be ineffective. Only 53% of the contact time with a speech and language therapist was direct (one to one), the rest was impairment based therapy. In contrast, all of the visitors’ time was direct contact, usually in conversation. In both groups, the frequency and length of contact time varied. We already know that the transfer from impairment based therapy to functional communication can be limited and varies across individuals.5 However, it is not possible to conclude from this trial that one to one impairment based therapy should be replaced. For that, a well defined impairment therapy protocol must be directly compared with a similarly well defined functional communication therapy, with an attention control.

Analysis and compensation for the joint effects of HPA nonlinearity, I/Q imbalance and crosstalk in MIMO beamforming systems

In this paper, we investigate the joint effects of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk, on the performance of multiple-input multiple-output (MIMO) transmit beamforming (TB) systems, and propose a compensation method for the three impairments together. The performance of the MIMO TB system equipped with the proposed compensation scheme is evaluated in terms of average symbol error probability and capacity when transmissions are performed over uncorrelated Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, length of pilot symbols and phase-shift keying modulation order.

Self-ratings and observer-ratings of social skill: a manipulation of state social anxiety in anxious and non-anxious children

The role of state and trait anxiety on observer ratings of social skill and negatively biased self-perception of social skill was examined. Participants were aged between 7 and 13 years (mean=9.65; sd=1.77; N=102), 47 had a current anxiety diagnosis and 55 were non-anxious controls. Participants were randomly allocated to a high or low anxiety condition and asked to complete social tasks. Task instructions were adjusted across conditions to manipulate participants’ state anxiety. Observers rated anxious participants as having poorer social skills than non-anxious controls but there was no evidence that anxious participants exhibited a negative self-perception bias, relative to controls. However, as participants’ ratings of state anxiety increased, their perception of their performance became more negatively biased. The results suggest that anxious children may exhibit real impairments in social skill and that high levels of state anxiety can lead to biased judgements of social skills in anxious and non-anxious children.

Children as caregivers

Caregiving is usually associated with adults’ responsibilities. Official statistics and research have demonstrated, however, that many children and young people in the global North and South have substantial, regular caring responsibilities for family members with chronic illnesses, impairments or other care needs. This chapter conceptualises children’s roles as ‘caregivers’ and the care work they do. It then analyses the available evidence on outcomes of children’s caregiving and the factors and processes influencing their involvement. While research reveals that caregiving may have positive as well as negative outcomes for children’s well-being, formal and informal safety nets are needed, especially in resource-limited settings, to alleviate children’s care work. Children’s and families’ experiences suggest that social protection measures and support for those being cared for as well as those providing care would help to ensure that caregiving does not have long-term negative impacts on children’s personal development, education, health, family relations, peer interactions, social participation, employment opportunities and socially expected transitions to adulthood.

Lesions impairing regular versus irregular past tense production

We investigated selective impairments in the production of regular and irregular past tense by examining language performance and lesion sites in a sample of twelve stroke patients. A disadvantage in regular past tense production was observed in six patients when phonological complexity was greater for regular than irregular verbs, and in three patients when phonological complexity was closely matched across regularity. These deficits were not consistently related to grammatical difficulties or phonological errors but were consistently related to lesion site. All six patients with a regular past tense disadvantage had damage to the left ventral pars opercularis (in the inferior frontal cortex), an area associated with articulatory sequencing in prior functional imaging studies. In addition, those that maintained a disadvantage for regular verbs when phonological complexity was controlled had damage to the left ventral supramarginal gyrus (in the inferior parietal lobe), an area associated with phonological short-term memory. When these frontal and parietal regions were spared in patients who had damage to subcortical (n = 2) or posterior temporo-parietal regions (n = 3), past tense production was relatively unimpaired for both regular and irregular forms. The remaining (12th) patient was impaired in producing regular past tense but was significantly less accurate when producing irregular past tense. This patient had frontal, parietal, subcortical and posterior temporo-parietal damage, but was distinguished from the other patients by damage to the left anterior temporal cortex, an area associated with semantic processing. We consider how our lesion site and behavioral observations have implications for theoretical accounts of past tense production.

Neural responses to emotional faces in women recovered from anorexia nervosa

Impairments in emotional processing have been associated with anorexia nervosa. However, it is unknown whether neural and behavioural differences in the processing of emotional stimuli persist following recovery. The aim of this study was to investigate the neural processing of emotional faces in individuals recovered from anorexia nervosa compared with healthy controls. Thirty-two participants (16 recovered anorexia nervosa, 16 healthy controls) underwent a functional magnetic resonance imaging (fMRI) scan. Participants viewed fearful and happy emotional faces and indicated the gender of the face presented. Whole brain analysis revealed no significant differences between the groups to the contrasts of fear versus happy and vice versa. Region of interest analysis demonstrated no significant differences in the neural response to happy or fearful stimuli between the groups in the amygdala or fusiform gyrus. These results suggest that processing of emotional faces may not be aberrant after recovery from anorexia nervosa.

Type 2 diabetes and impaired glucose tolerance are associated with word memory source monitoring recollection deficits but not simple recognition familiarity deficits following water, low glycaemic load, and high glycaemic load breakfasts.

Isolated source monitoring recollection deficits indicate that abnormalities in glucose metabolism are not detrimental for global episodic memory processes. This enhances our understanding of how metabolic disorders are associated with memory impairments.